Lipids Essay

Baked products serve as one of the main staple foods for consumers, and lipids play important functional and nutritional roles in these products (Chung and Pomeranz 1983; Wainwright 1999). Lipids in baking contribute to characteristics such as tenderness, moisture, mouthfeel, flavor, structure, and shelf life. During processing, lipids affect air incorporation, lubrication, and heat exchange (Stauffer 1998; Rogers 2004). In pie crusts, lipids with a proper solid character and melting point contribute to flakiness and tenderness (Ghotra and others 2002). In cakes, lipids are important for air incorporation (Hartnett and Thalheimer 1979 II), affecting volume and texture of finished cakes (Stauffer 1998). Air incorporation is equally important

During the last two decades consumers have become aware of the nutritional quality of foods and demand foods formulated with healthier lipid sources. The USDA and FDA recommend consuming less than 10% of calories from saturated fatty acids (SFA), replacing them with monounsaturated (MUFA) and polyunsaturated (PUFA) fatty acids, and reducing trans-fat (TFA) intake as much as possible (USDA and USDHHS 2010). Generally, animal fats (e.g. lard) are more saturated than plant oils (e.g. soybean oil), and the ratio of PUFAs to SFAs is much lower (Chung and Pomeranz

FAME composition of lipids is shown in Table 2. The major component of B is palmitic acid (C16:0) which is approximately 32% of the total fat. Oleic acid (C18:1) is the predominant fatty acid in L and M (37% and 57%, respectively), while SBO, APS and IES contain predominantly linoleic acid (C18:2; 53%, 44% and 42%, respectively). APS and IES have approximately the same content of SFA, MUFA and PUFA, with slightly higher values of SFA for IES due to higher stearic acid content. In addition, IES contains less palmitic acid, oleic and linoleic acid. Functional properties of lipids are summarized in Table 3. Lipid sources with the lowest melting points are M (31.0 ± 1.9°C) and B (33.0 ± 0.8°C), while APS has the highest (43.7 ± 1.9°C). Similarly, peak melting temperature (Tp) is highest in APS. Interestingly, even though APS and IES have similar chemical composition in terms of SFA, MUFA and PUFA, their melting points are significantly different (P<0.05) with IES having a melting point approximately 7°C lower. Fats with similar FAME composition can have different physicochemical properties due to differences in triacylglycerol composition. IES has the highest δ value (P<0.05),